THURSDAY, Sept. 18 (HealthDay News) -- High daily doses of calcium supplements may reduce lead levels in the blood of pregnant women and cut down on fetal and infant exposure, a new report suggests.

The study, published online in Environmental Health Perspectives, found that women who take 1,200 milligrams of calcium daily have up to a 31 percent reduction in lead levels.

Women who used lead-glazed ceramics or with high bone lead levels showed the largest reductions, while the average reduction was about 11 percent.

"We and others have previously shown that during pregnancy, mothers can transfer lead from their bones to their unborn -- with significant adverse consequences -- making maternal bone lead stores a threat even if current environmental lead exposures are low," principal investigator Howard Hu, chairman of the University of Michigan's Department of Environmental Health Sciences, said in a news release issued by the school. "This study demonstrates that dietary calcium supplementation during pregnancy may constitute a low-cost and low-risk approach for reducing this threat."

Exposure to lead during fetal development and infancy can cause low birth weight or slow weight gain after birth, cognitive defects such as lower intelligence scores, lower motor and visual skills, or even miscarriage. Damage from lead exposure and poisoning is usually permanent, the researchers said.

Bone lead can stay in the body for decades, and the fetus or nursing infant can still be at great risk from maternal stores of lead even with minimal environmental exposure, the researchers said.

"The bottom line is that obstetricians and pediatricians should consider adding calcium supplementation to the prenatal vitamins normally recommended in pregnant women, particularly if their patients have a significant history of environmental or occupational lead exposure," Hu said.

The study, conducted with 557 mostly low- to moderate-income women recruited from Mexican prenatal clinics, found reductions in blood lead levels were more evident in the second trimester (14 percent) than in the third trimester (8 percent).

-- Kevin McKeever

SOURCE: University of Michigan School of Public Health, news release, Sept. 10, 2008